This document summarizes research on the alkaloid atropine. It is derived from plants like Atropa belladonna and has the molecular formula C17H23NO3. Atropine breaks down into tropic acid and tropine when reacted with barium hydroxide. Tropic acid was shown to have the structure of a benzene ring with a side chain. The structure of tropine was confirmed to be a reduced pyridine nucleus based on evidence from oxidation and synthesis reactions. Willstatter and Robinson both provided syntheses that validated the proposed structure of tropine.

1. CENTRAL UNIVERSITY OF KASHMIR
DEPARTMENT OF ZOOLOGY
NAME : MUSHTAQ AHMAD KHAN
ENROLLMENT NO: 1915CUKMR23
SEMESTER. : 6TH
TOPIC. : ATROPINE
DATE OF SUBMISSION:1ST JULY 2022
SUBMITTED TO. : DR. SKINDAR SIR

2. ATROPINE

3. •It is a Solanaceous alkaloid .
•Molecular Formula:C17H23NO3
•Melting Point :118°C
•It occurs in Atropa belladonna along with Hyoscyamine .
•Hyoscyamine is optically active ( levorotatory ) but readily recimises to
atropine when warmed with ethanolic alkaline solution.
•Thus atropine is (+/-) hyoscyamine.
•Atropine on reaction with Barium Hydroxide gives plus minus tropic
acid and plus tropine.

4. TROPIC ACID
• Molecular Formula. C9O3H10
• Melting point 117°C
• It is a saturated compound
• Usual tests Show that it contains one carboxyl group and one alcoholic group.
• When heated strongly,It loses a molecule of water and forms atropic acid and
atropic acid on oxidation gives benzoic acid.
• This Shows that tropic acid and atropic acid contains benzene ring with one side
chain.

5. • 1st is cinnamic acid.
• 2nd must be atropic acid as addition of water molecule to this gives
tropic acid.
• Two structures are possible for tropic acid.

6. •Tropic acid has been shown to be 4th by synthesis from
acetophenone by Mackenzie and Wood.

7. • 3rd is atrolactic acid and it’s dehydration to 2nd confirms the
structure of atropic acid .
• It should be noted that addition of HCl takes place contrary to
markownikoff`s rule .
• Blicke et al have also synthesized the tropic acid by boiling
phenylacetic acid with isopropylmagnesium chloride in etheral
solution and then treating the product with formaldehyde.

8. TROPINE
• Also called Tropanol.
• Molecular Formula:.. C
• Melting point 63°C.
• Behaves as saturated compound with one alcoholic group.
• Structure was investigated by Ladenberg who showed molecule contains reduced
pyridine nucleus.

9. •The formation of methyl chloride indicates presence of N-methyl
group.
•Isolation of 2-ethylpyridine shows the presence of this nucleus .
•On this evidance Ladenberg proposed the following structures.

10. • Merling by oxidation of tropine with cromium trioxide obtained plus minus tropic
acid.
• Tropic acid is a dicarboxylic acid.
• There is no loss of carbon in its formation ,the hydroxyl group in tropine must
therefore be in a ring system.
• Thus Ladenburg formula is untainable.
• Merling proposed the following structures

11. •Willstatter examined the oxidation products of tropine obtained as follows .
Tropinone behaved as a ketone .
Willstatter also showed that tropinone forms dibenzalidine derivative with
benzeldehyde and di-oximino derivative with amylnitrite and Hydrochloric
acid.
Thus tropinone contains CHCOCH groups and it follows that Merling formula
is untainable.
Willstatter proposed the following structure of tropinone.
This structure fit the facts best and was supported by evidences.

12. • The structure of tropine has been confirmed by synthesis,one by Willstatter and other by
Robinson.
• Robinson synthesis.
• When mixture of succinaldehyde,methylamine and acetone is allowed for 30 minutes,
tropinone is produced

13. •
+

14. REFRENCE.
•Jonathan Clayden ( University of Manchester )
• Nick Greeves (University of Liverpool)
• Stuart Warren (University of Cambridge)
•Organic chemistry Volume II by I.L .Finar

15. THANK YOU